The present invention relates to a concrete form structural supporting system, and more particularly, to a structural supporting or adjustable waler system for use as a temporary support, such as in concrete falsework forming for bridge deck, concrete slab construction and the like.
Various types of structural undergirders or spanning systems are used to underlie concrete falsework forms in bridge deck and concrete slab construction and the like. Most of such spanning systems incorporate telescopic members that also serve as a structural supporting components in the system. For example, one such system made by Rex-Spannall, Inc. of Milwaukee, Wis. includes a telescopic girder assembly in which tapered bearing flanges on an inner member slidably telescopically interfit relative to double bearing flanges on an outer member. To reduce the weight of the overall telescopic girder assembly, the side walls of the outer member are open except for a continuous reinforcing bar extending in a side-wave pattern so as to interconnect the upper and lower portions of the outer member. This provides an open side wall which reduces the weight of the outer member, and yet provides desired load bearing capacity in a minimum-weight member. Despite the reduction in weight of the outer and inner members in such a device, the outer member is typically provided with spaced supporting wheels to assist in telescopically adjusting the inner and outer members relative to one another, as may be desired.
Another type of spanning system, shown in the Alcoa-Hico system, includes adjustable, aluminum shoring beams that have been designed and engineered to support concrete slab forms of various size thickness. The Alcoa-Hico beam is an adjustable horizontal aluminum shoring beam composed of two sections: an I beam section which telescopes into a box section. Both sections are locked in place by means of a steel bolt threaded through a steel nut plate attached to the lower chord of the box section. This locking arrangement enables the assembled beam sections to act in unison.
While such aforementioned spanning or structural supporting systems have many inherent advantages including being adjustable, providing good load bearing characteristics, providing positive setting of the beams, and being durable for long use, there are some inherent drawbacks. First of all, the above described spanning or structural supporting systems are relatively heavy and cumbersome, and this not only creates handling problems during installation, but also in removal and storage of such devices. Such prior art devices are also very costly because of the necessity of using substantial amounts of material to provide the necessary load bearing support that is desired, although both of the above described systems have sought ways, in either the construction of the device or in the type of material used, to minimize the amount of material, and therefore, the cost of such units. Despite these attempts, the cost of such prior art devices is higher than it needs to be. Finally, such prior art devices have not provided the desired adjustability and versatility, and thereby have limited the productivity of construction workers in using such prior art systems.